According to the prior art, to fix various kinds of members to another member, a fixing member such as a screw is used, or a fixing means such as a threaded portion is provided directly on various kinds of members to use the various kinds of members themselves as fixing members.
For instance, as shown in FIG. 19, a proximity sensor 99 described in the following patent literature 1 has a structure with a lead switch 98 buried in soft resin 97 and a surface covered with hard resin 96.
To attach this proximity sensor 99 to, for example, an air cylinder, as shown in FIG. 20, a groove 94 with its cross section formed into an approximately round shape corresponding to the shape of the cross section of the proximity sensor 99 is formed on a mount 95 in advance, and the proximity sensor 99 is housed in this groove 94 and fixed using a screw 92. More specifically, before the proximity sensor 99 is placed in the groove 94, the screw 92 is inserted into a screw hole 93 formed at the front of the proximity sensor 99 and screwed to the extent that it does not get caught by the groove 94.
In this state, the proximity sensor 99 is inserted from an end 94a of the groove 94 and slid through the groove 94 to a desired detection point. At the same time, a protruding portion 99a of the proximity sensor 99 and a lead wire 91 are moved through an opening 90 of the groove 94. With the proximity sensor 99 accurately aligned at a desired detection point, the screw 92 is fastened to fix the sensor at that position.
As shown in FIG. 21, when the screw 92 is made to abut on the bottom 94b of the groove 94 and fastened, a reaction force of the screw 92 pushes up the proximity sensor 99 toward the opening 90, and an outer surface of the proximity sensor 99 with its cross section formed into an approximately round shape is pressed against a circumference of the opening 90 on the inner wall surface of the groove 94.
Then, when further fastened, the screw 92 is strongly pressed against the bottom 94b of the groove 94 by a screwing force against the screw hole 93; accordingly, the proximity sensor 99 is firmly fixed at the desired detection point.